private Snapshot Apply(Snapshot original, List <BlockHeader> headers, ulong epoch)
{
// Allow passing in no headers for cleaner code
if (headers.Count == 0)
{
return(original);
}
// Sanity check that the headers can be applied
for (int i = 0; i < headers.Count - 1; i++)
{
if (headers[i].Number != original.Number + i + 1)
{
throw new InvalidOperationException("Invalid voting chain");
}
}
// Iterate through the headers and create a new snapshot
Snapshot snapshot = (Snapshot)original.Clone();
foreach (BlockHeader header in headers)
{
// Remove any votes on checkpoint blocks
long number = header.Number;
if ((ulong)number % epoch == 0)
{
snapshot.Votes.Clear();
snapshot.Tally.Clear();
}
// Resolve the authorization key and check against signers
Address signer = header.Author;
if (!snapshot.Signers.ContainsKey(signer))
{
throw new InvalidOperationException("Unauthorized signer");
}
if (HasSignedRecently(snapshot, number, signer))
{
throw new InvalidOperationException($"Recently signed (trying to sign {number} when last signed {snapshot.Signers[signer]} with {snapshot.Signers.Count} signers)");
}
snapshot.Signers[signer] = number;
// Header authorized, discard any previous votes for the signer
for (int i = 0; i < snapshot.Votes.Count; i++)
{
Vote vote = snapshot.Votes[i];
if (vote.Signer == signer && vote.Address == header.Beneficiary)
{
// Uncast the vote from the cached tally
Uncast(snapshot, vote.Address, vote.Authorize);
// Uncast the vote from the chronological list
snapshot.Votes.RemoveAt(i);
break;
}
}
// Tally up the new vote from the signer
bool authorize = header.Nonce == Clique.NonceAuthVote;
if (Cast(snapshot, header.Beneficiary, authorize))
{
Vote vote = new Vote(signer, number, header.Beneficiary, authorize);
snapshot.Votes.Add(vote);
}
// If the vote passed, update the list of signers
Tally tally = snapshot.Tally[header.Beneficiary];
if (tally.Votes > snapshot.Signers.Count / 2)
{
if (tally.Authorize)
{
snapshot.Signers.Add(header.Beneficiary, 0);
}
else
{
snapshot.Signers.Remove(header.Beneficiary);
}
// Discard any previous votes the deauthorized signer cast
for (int i = 0; i < snapshot.Votes.Count; i++)
{
if (snapshot.Votes[i].Signer == header.Beneficiary)
{
// Uncast the vote from the cached tally
if (Uncast(snapshot, snapshot.Votes[i].Address, snapshot.Votes[i].Authorize))
{
// Uncast the vote from the chronological list
snapshot.Votes.RemoveAt(i);
i--;
}
}
}
// Discard any previous votes around the just changed account
for (int i = 0; i < snapshot.Votes.Count; i++)
{
if (snapshot.Votes[i].Address == header.Beneficiary)
{
snapshot.Votes.RemoveAt(i);
i--;
}
}
snapshot.Tally.Remove(header.Beneficiary);
}
}
snapshot.Number += headers.Count;
// was this needed?
// snapshot.Hash = BlockHeader.CalculateHash(headers[headers.Count - 1]);
snapshot.Hash = headers[headers.Count - 1].Hash;
return(snapshot);
}
public Snapshot Apply(List <BlockHeader> headers)
{
// Allow passing in no headers for cleaner code
if (headers.Count == 0)
{
return(this);
}
// Sanity check that the headers can be applied
for (int i = 0; i < headers.Count - 1; i++)
{
if (headers[i].Number != Number + (UInt256)i + 1)
{
throw new InvalidOperationException("Invalid voting chain");
}
}
// Iterate through the headers and create a new snapshot
Snapshot snapshot = Clone();
foreach (BlockHeader header in headers)
{
// Remove any votes on checkpoint blocks
UInt256 number = header.Number;
if ((ulong)number % Config.Epoch == 0)
{
snapshot.Votes.Clear();
snapshot.Tally = new Dictionary <Address, Tally>();
}
// Resolve the authorization key and check against signers
Address signer = header.Author;
if (!snapshot.Signers.ContainsKey(signer))
{
throw new InvalidOperationException("Unauthorized signer");
}
if (HasSignedRecently(snapshot, number, signer))
{
throw new InvalidOperationException("Recently signed");
}
snapshot.Signers[signer] = number;
// Header authorized, discard any previous votes from the signer
for (int i = 0; i < snapshot.Votes.Count; i++)
{
Vote vote = snapshot.Votes[i];
if (vote.Signer == signer && vote.Address == header.Beneficiary)
{
// Uncast the vote from the cached tally
snapshot.Uncast(vote.Address, vote.Authorize);
// Uncast the vote from the chronological list
snapshot.Votes.RemoveAt(i);
break;
}
}
// Tally up the new vote from the signer
bool authorize = header.Nonce == Clique.NonceAuthVote;
if (snapshot.Cast(header.Beneficiary, authorize))
{
Vote vote = new Vote(signer, number, header.Beneficiary, authorize);
snapshot.Votes.Add(vote);
}
// If the vote passed, update the list of signers
Tally tally = snapshot.Tally[header.Beneficiary];
if (tally.Votes > snapshot.Signers.Count / 2)
{
if (tally.Authorize)
{
snapshot.Signers.Add(header.Beneficiary, 0);
}
else
{
snapshot.Signers.Remove(header.Beneficiary);
}
// Discard any previous votes the deauthorized signer cast
for (int i = 0; i < snapshot.Votes.Count; i++)
{
if (snapshot.Votes[i].Signer == header.Beneficiary)
{
// Uncast the vote from the cached tally
snapshot.Uncast(snapshot.Votes[i].Address, snapshot.Votes[i].Authorize);
// Uncast the vote from the chronological list
snapshot.Votes.RemoveAt(i);
i--;
}
}
// Discard any previous votes around the just changed account
for (int i = 0; i < snapshot.Votes.Count; i++)
{
if (snapshot.Votes[i].Address == header.Beneficiary)
{
snapshot.Votes.RemoveAt(i);
i--;
}
}
snapshot.Tally.Remove(header.Beneficiary);
}
}
snapshot.Number += (ulong)headers.Count;
snapshot.Hash = BlockHeader.CalculateHash(headers[headers.Count - 1]);
return(snapshot);
}